Locomotive boiler firebox



Oct. 1, 1940. G. J CHRISTENSON 2,216,227

LOCOMOTIVE BOILER FIREBOX Filed March 17. 1939 Patented Oct. 1, 1940 UNITED STATES PATENT OFFICE 2,216,227 LOCOMOTIVE BOILER FIREBOX Application March 17,

5 Claims.

This invention relates to improvements in locomotive boiler fireboxes and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

One of the objects of the invention is to provide a locomotive firebox of such construction as to obtain the greatest possible additional heating area without increasing the size of the firebox and the undesirable reactions that would accompany such an increase in size.

Another object of the invention is to provide a locomotive boiler firebox including means for providing better water circulating action between both side water legs and the boiler water space above the crown sheet and which means is so constructed as to rigidly brace the crown sheet but at the same time permit the relative movement that occurs between the crown sheet and the side sheets under the action of temperature 20 .changes in said sheets.

Again, it is an object of the invention to provide means in the firebox that increases the water steaming and circulating action of the associated boiler and which means is so made and arranged in the firebox as to interpose a minimum of resistance to the flow of gases toward the front end, and at the same time aids in the admixture of the gases by dividing the same into a plurality of streams and so directs said streams that the temperatures are equalized at the front and rear of said means thus avoiding undesirable temperature stresses in the metal thereof.

Again, it is a further object of the invention to provide a novel water steaming and circulating element for use in a locomotive boiler firebox for increasing the water circulating and steaming action thereof and which element is so constructed as to make it possible and practicable to include a rigidifying diaphragm therein that also functions to reduce water turbulence in the element.

The above mentioned objects of the invention, as well as others, together with the advantages thereof will more fully appear as the specification proceeds.

In the drawing:

Fig. 1 is a longitudinal vertical sectional view through a locomotive boiler firebox embodying the preferred form of the invention.

Fig. 2 is a transverse vertical sectional view through a part of the firebox appearing in Fig. 1, as taken on the line 2-2 of Fig. 1.

Fig. 3 is a horizontal detail sectional view on an enlarged scale through a part of one of the water circulating and steaming elements employed in 1939, Serial No. 262,328

the firebox, the plane of said section being indicated by the line 3-4 of Fig. 2.

Fig. 4 is a view similar to Fig. 3 and illustrates a modified form of water steaming and circulating element.

Referring now in detail to that embodiment of the invention illustrated in Figs. 1 to 3 inclusive of the accompanying drawing, the firebox therein shown includes a crown sheet l0, inner side sheets H, inner back sheet l2 and inner throat l sheet l3 and flue sheet l4.

I5 is the outer rear boiler sheet, IS the outer side sheets, and I1 outer throat sheet. The said sheets cooperate with the top sheet of the boiler in forming the back water leg l8, side water legs I9 and the front throat respectively, all in communication with the water space 2| of the boiler. 22 is the mud ring. The inner and outer back sheets are formed to provide a conventional fuel door opening as appears in Fig. 1.

In the firebox is located one or more elements, each having a lower portion with ends opening through the side sheets and a plurality of spaced apart upper portions that connect said lower portion with the boiler water space above the crown sheet. The number of such elements depends upon the size and type of firebox. As shown in Fig. 1, there are five of such elements 23-44- 25-28 and 21 spaced apart longitudinally and extending transversely of the firebox.

Said elements are similar but differ principally only in the length of certain of the parts thereof. Therefore, a description of one will sufiice. The element 25 for example, includes a hollow lower portion having a pair of outwardly and 5 downwardly extending tubular inlet legs 28-48 which open through and are welded in associated side sheets ll. 29-29 indicate the upwardly extending tubular outlet legs of the element, the top ends of which open through and are welded in the crown sheet. The outlet legs are spaced apart, one on each side of the longitudinal median line of the firebox, with their axes in planes between adjacent longitudinal rows of stays.

The lower ends of the outlet legs 29 curve inwardly toward each other, connecting at a junction-like mid portion 30 with the top central part of the lower portion. The opposed inner surfaces of the legs 29 join as a crotch 3| that forms the top for the mid portion 30.

The inlet legs 2828 are disposed at the diverging inclinations desired for the two sides of the arch, when such an arch is used in the firebox. When the inclination causes theends of said legs to approach the side sheets at too acute an angle, said ends are bent slightly, as in Fig. 2 to approach said side sheets at an angle better adapted for welding in the sheets.

The outlet legs 29 are parallel and project through and are welded in the crown sheet. In Figs. 1 and 2 these legs are circular tubes. Certain of the radial stays of the boiler are omitted or removed from the crown sheet and the openings for said legs are so disposed as to require the removal of but four stays for each leg.

It is to be noted that each of the elements before mentioned provides a four point spaced apart operative connection between portions of the crown sheet and portions of the side sheets and by reason of this connection, said portions are capable of relative movement under temperature changes. tions as a rigid brace effect for the crown sheet and to increase such effect as well as to obtain other benefits as will soon appear, a diaphragm member 32 is arranged centrally in the junction portion 30 of the element. This member 32 extends from top to bottom and from the front to the rear of the junction portion 30 so as to completely separate or divide the interior of said junction portion into. two lateralpassageways 33-33 respectively, which form individual inlets for the outlet legs 29-29 and which inlets are in communication with the associated inlet legs 2828 of the element.

As here shown, each element is made from a pair of front and rear counterparts of sheet metal, each of which is of substantially a semi-circular cross section, at any point therein and the matched edges thereof are butt welded together at 34 as appears in Fig. 3. The diaphragm member 32 may be assembled in place in a number of different ways. After the member 32 has been cut to the desired patterned shape, it may be welded in place as at 35 in Fig. 3 to one of the counterparts of the element before said counterparts are welded together. Another way in which the diaphragm may be assembled in place, is to make up the element by butt welding the edges of the counterparts together as previously mentioned and then cut through the mid portion 30 so as to divide the same into right and left hand parts. Thereafter a diaphragm plate 32a is welded in place as at 35a, at the cut which provided the right and left hand parts. This arrangement appears in Fig. 4.

When the structure shown in Fig. 3 is employed, the diaphragm 32 is located entirely within the junction portion 30 so that no line of weld is present upon the outside of the junction portion. When the structure shown in Fig. 4 is employed, the line of the weld 35a which covers the edges of the diaphragm 32a is present around the vertical central peripheral line of the junction portion 30.

In either instance thediaphragm materially rigidifies the element as to the bracing eifect and in either instance, the diaphragm acts as a separator or partition in said junction portion whereby each outlet leg 29 has an individual inlet communication with an inlet leg 28. Thus water entering the leg from the side water legs, flows upwardly toward the portion 30 to meet the diaphragm 32 or 32a. which directs it into the passageways 33, each of which forms the inlet end of the associated outlet leg. Therefore, it is apparent that the two streams of water passing through the inlet legs 28, do not meet and commingle at the junction portion 30 so that there is no resulting turbulence at this point.

Furthermore, each element func As shown in Fig. 1, the element 23 has the least vertical dimension and the element 24 has a greater one. Elements 25-48 have still greater vertical dimensions and element 21 has the greatest one. Openings are made in the side sheets ii to receive the element ends. These openings are arranged on a line having that inclination desired in the arch. When the various elements are in place in the firebox, the longitudinal dimensions of both the inlet and outlet legs of the various elements increase successively toward the front end of the firebox.

The elements are made with the greatest longitudinal dimension of the various legs and then the legs are cut of! at such lengths as will adapt each element for its particular place in the firebox. The outlet legs 29-29 may be made to diverge upwardly and outwardly from the Junetion part 30 but the parallel relation of said legs is preferred because in removing the top ends thereof for fitting in the firebox, the lateral spacing does not vary and the crown sheet bolts requiring removal are kept in line. v

The-products of combustion in their flow toward the flue sheet have a more intimate engagement with the entire surfaces of the outlet legs 29 of the various elements and there is no blind space at the front side of the outlet legs to there produce a vacuous condition. Such blind spaces are objectionable as they disturb draft action through transverse eddies. The present structure not only avoids eddies which disturb draft action but the water in said legs absorbs more heat units to give a better water circulating and steaming action.

Because the products of combustion do flow around and in relatively intimate relation to all parts of the element, the temperature on both sides of the element is more nearly equalized and stresses produced by differences in temperatures are minimized. I

When certain relative movement occurs between the sheets of the firebox it is due to stresses developed in temperature changes. The circulating elements herein are relatively flexible to yield to and accommodate such movement without producing seam cracks or fractures either in parts of the elements themselves or in the sheets of the firebox or in the welds which secure said elements in said sheets of the firebox. This is possible because of the pair of inlet legs and the spaced pair of outlets. At the same time, however, said elements have a vertically bracing effect for the crown sheet, which is increased by virtue of the diaphragms 32-32a in each element.

In operation, colder water from the side water legs enters the inlet legs 28 as two streams which are kept separate at the mid portion 30 to pass out through the outlet legs 29 into the water space above the firebox. Thus, a large volume of water is constantly flowing through the junction portion which aids in keeping the surfaces clean. Hence, no sediment can accumulate in the element so that burning out of the element is substantially, if not entirely, eliminated.

The invention, of course, is also applicable for use in locomotive boiler fireboxes of the combustion chamber type and therefore in the claims, the term side sheets is intended to include not only the side sheets of the firebox proper, but also the sheets at the sides of the combustion chamber.

While in describing the invention I have referred in detail to the form and arrangement of the parts involved, the same is to be considered iii only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. In combination with a locomotive boiler firebox including a crown sheet and side sheets, a water steaming and circulating element in the firebox comprising an arched lower tubular portion extending transversely of the firebox with the outer ends thereof opening through the side sheets, and a plurality of spaced upper tubular portions, the top end of each of which opens separately through the crown sheet and the bottom ends of which converge toward each other to provide a junction portion divided into individual non-communicating inlet passageways each of which is in separate communication with said lower tubular portion.

2. In combination with a locomotive boiler firebox including a crown sheet and side sheets, a water steaming and circulating element in the firebox comprising an arched lower tubular portion extending transversely of the firebox with the outer ends thereof opening through the side sheets, a plurality of spaced upper tubular portions, the top end of each of which opens separatelythrough the crown sheet, means providing a junction portion connecting the bottom ends of said spaced upper tubular portions with a part of said arched lower tubular portion, and means in said junction portion separating the same internaIly into a plurality of passageways, each individually connecting the bottom end or one of said spaced upper tubular portions with an associated part of said arched lower tubular portion.

3. In combination with a locomotive boiler firebox including a crown sheet and side sheets, a water steaming and circulating element in the firebox comprising an arched lower tubular portion extending transversely of the firebox with the outer ends thereof opening through the side sheets, a plurality of spaced upper tubular portions, the top end of each of which opens separately through the crown sheet, means providing a junction portion connecting the bottom ends of said spaced upper tubular portions with a part of saidarched lower tubular portion, and a vertically disposed diaphragm in said junction portion separating the same internally into a plurality of passageways each individually connecting the bottom end of one of said upper tubular portions with an associated part of said arched lower tubular portions.

4. As an article of manufacture, a water steaming and circulating element for a locomotive boiler firebox made from a pair of similarly shaped parts secured in pressure tight engagement edge-to-edge and providing a plurality of downwardly and outwardly diverging tubular portions forming an arch-like structure adapted to extend transversely of the firebox with its ends opening through the side sheets of the firebox and also providing a plurality of spaced substantially tubular portions adapted to extend through the crown sheet and further providing a junction portion operatively connecting the bottom end of said spaced substantially tubular portions with said downwardly and outwardly diverging tubular portions, and means in said junction portion for stiffening the same in a vertical direction and for dividing said junction portion into a plurality of passageways, whereby separate communication is afforded between each downwardly and outwardly extending portion and each of said spaced substantially tubular portions.

5. As an article of manufacture, a water steaming and circulating element for a locomotive boiler firebox comprising at least a pair of opposed tubular legs extending outwardly and downwardly at least in part, to provide an archlike structure adapted for arrangement transversely of the firebox with the ends of said legs opening through the side sheets thereof and including at least two laterally spaced upwardly extending tubular legs, the top end of each leg being adapted for engagement in and to open through the crown sheet of the boiler, and the bottom'ends of which are connected by a junction portion with said first mentioned pair of legs at substantially the mid portion thereof, and means providing a vertical partition in said junction portiondividing the same into two lateral passages, each affording separate communication between one of said first mentioned legs and one of said upwardly extending tubular legs.

GUST J. CHRISTENSON. 

